Produce an event according to the given list of time deltas and
event values. The time deltas are relative to each other, hence from
the perspective of switching in [(1, a), (2, b), (3, c)]
produces the event a after one second, b after three seconds
and c after six seconds.

Note that this event transformer has to keep all delayed events in
memory, which can cause event congestion. If events are fed in
faster than they can be produced (for example when the framerate
starts to drop), it will leak memory. Use delayEventSafe to
prevent this.

Delay events by the time interval in the left signal. The event
queue is limited to the maximum number of events given by middle
signal. If the current queue grows to this size, then temporarily no
further events are queued.

As suggested by the type, this maximum can change over time.
However, if it's decreased below the number of currently queued
events, the events are not deleted.